(Disclaimer: I am biased since my company developed and markets "ROMlib" and "Executor," two products that predate Quorum's similar Latitude and Equal. None of our or Quorum's products require the user to copy the Apple ROMs or System File. Please note that currently our products are only supported on NeXT computers, but this will change within six months.)

Adam C. Engst writes in TidBITS-108:

Finally, since Quorum based the display parts of Latitude on Adobe's Display PostScript, there is no conflict with Apple's patented QuickDraw software (which is why most other emulators have required that you find some Mac ROMs to pop in).

US Patent #4,622,545 covers Apple's region code. If you take the claims in that patent (there are 35) at face value, then anyone that attempts to be compatible with the Mac will either have to get permission to use the patented technology or be in violation of the patent. It is an absurd patent that for all practical purposes locks up the data structure itself. So, even though Quorum doesn't use regions for most of its work, since it has the ability to read regions when processing PICTs it is in violation (assuming there's no secret agreement between Apple and Quorum). Apple has done similar things with their HFS structure in England. They have a patent there, which if taken at face value, prohibits anyone from reading or writing HFS compatible disks. [Adam: Note that several companies including Hydra (Mac emulator on a PC) and Gadgets By Small (Mac emulator on an Atari ST) already market products that do this.]

I believe there are two real reasons that other emulators require Mac ROMs.

It is much easier to use someone else's code than to rewrite the code yourself. Whether or not you choose a different "look and feel," as Quorum does, or you intentionally do exactly what the application code is asking for, as we do, rewriting the ROMs is a major achievement. It is especially difficult since the Mac OS is a hodgepodge of code that has several side-effects that an emulator must duplicate if it expects to run real world applications.

The second reason has to do with "look and feel" copyright (not patent) issues. The basic claim is that by using legitimate ROMs, the right to the look and feel is transferred with the ROMs. Apple hasn't challenged the rights of people who have acquired Mac ROMs to use them in other devices (although there was a challenge related to who can sell Mac ROMs). The implications here are significant. Apple is in effect admitting that they don't totally own the rights to the "look and feel" or else they would be able to shut down these other companies. In fact, if Apple had made an explicit claim for the "look and feel" in the early days of development, warning developers that "... the look and feel of your product ... is commingled with the look and feel of our product ... and hence can't be used on any platform other than what we specify ..." then, perhaps, they would have the right not only to attack clone makers but also companies that hack up Macs and put them in boxes that Apple doesn't like. Of course if Apple had done that in the early days, these policies would have scared numerous developers away, perhaps causing the Mac to fail.

Copyright and patent issues are very difficult indeed. There have been exceedingly few cases that have actually gone to trial and none of them addressed the specific issue of whether or not the look and feel of an application belongs to the application writer or the operating system vendor. I bring this up to point out that Quorum may not be in the clear as much as the original article implies and to reassure people who are interested in our technology that we are equally aware of the legal implications of what we're doing and that we too believe we're totally in the clear. Quorum has chosen to alter the "look and feel" of applications built with Latitude or run under Equal; we have chosen not to. Films that were shot in black and white can now be "colorized," and some people prefer colorized films. However others prefer to be true to the original creation of the producers, directors and cinematographers. When it comes to computer software there are more concerns than those aesthetic; there are manuals to rewrite and people to retrain. The nineties are going to be interesting.